Alexis Sanchez has not played since the Copa America Centenario, when he was named player of the tournament despite going off injured in the final. Photo: Getty Images

The wait for signings goes on, but Arsenal will at least be boosted by the return of two key players for its penultimate match of preseason, away at Norwegian side Viking FK on Friday. After a two-game excursion to the United States, which saw victories over the MLS All-Stars and Mexican giants Chivas, Alexis Sanchez and Aaron Ramsey have begun training and are a part of the squad that has traveled to Norway.

Ramsey is back after being given extra time off following his starring role in Wales' run through to the semifinals of Euro 2016. But Sanchez back out on the pitch will be a particularly welcome sight. The Chilean's delayed start to preseason was down to an ankle injury picked up in the final of the Copa America Centenario, but, having been linked with a transfer to Juventus for much of the summer, some Arsenal fans might have feared they had seen the last of the former Barcelona man in a Gunners shirt.

The fact that, like Mesut Ozil, who will not feature in Norway, Sanchez has has yet to extend a contract that has less than two years to run, remains a major concern. Arguably, Arsenal need Sanchez now more than ever. With Olivier Giroud still recuperating from Euro 2016 and the club continuing to bungle in its efforts to land another striker, Arsenal face going into the start of the Premier League season with a serious lack of firepower.

Indeed, after Theo Walcott failed to find the net in three preseason appearances in the central striking role, Sanchez could well be earmarked as the man to lead the attack when Arsenal face Liverpool a week on Sunday.

It is not only up front where there are concerns. The dearth of striker options is replicated at center-back, where a serious injury to Per Mertesacker has left Wenger desperately searching for an experienced replacement in the transfer market.

Amid plenty of unrest surrounding the club, the performances of Alex Oxlade-Chamberlain in preseason have provided a welcome bright spot. The midfielder scored superb goals against both Lens and Chivas and, after a string of injury problems and mediocre form, has looked determined to make up for lost time and stake his claim for a regular starting role this season.

“This is a very important season for Alex,” Wenger said after the win over Chivas in Los Angeles on Sunday. “He was out for a very long time, I'm cautious with him at the moment but he's getting better in every game and that's good to see.”

After the game against Viking, Arsenal will just have one more match, against Manchester City on Sunday, before beginning its latest attempt to end its long wait for a Premier League title. While Viking may not be the strongest opposition, it is a team that is right in the middle of its season and should certainly be physically sharp.

Viking currently sits seventh in the 16-team Norwegian Tippeligaen. The focus for coach Kjell Jonevret on Friday could well be avoiding injury, with Viking facing a league game against Sogndal two days later.